Stratum soil deformation monitoring device and method in hydrate generation and exploitation process

Abstract

The invention relates to a stratum soil deformation monitoring device in a hydrate generation and exploitation process. The stratum soil deformation monitoring device is characterized by comprising a low-temperature chamber, a hydrate generation chamber, a simulated exploitation shaft, optical fibers, deformation monitoring systems, temperature compensation systems, an optical fiber demodulator and an upper computer, wherein the hydrate generation chamber for placing a substance to be monitored is arranged in the low-temperature chamber; the simulated exploitation shaft is longitudinally arranged in the center of the bottom of the hydrate generation chamber; a plurality of deformation monitoring systems and temperature compensation systems are arranged on the outer side of the simulated exploitation shaft at intervals in a sleeving manner; the corresponding optical fiber is arranged between each deformation monitoring system and the corresponding temperature compensation system; the optical fiber demodulator is connected with each optical fiber and is used for emitting light with specific frequency and demodulating the light frequency of the light propagated in each optical fiber to obtain demodulated light frequency; and the upper computer is connected with the optical fiber demodulator and is used for obtaining soil strain distribution of the substance to be monitored according to the demodulated light frequency. The stratum soil deformation monitoring device can be widely applied to the field of hydrate exploitation monitoring simulation.

Description

technical field [0001] The invention relates to a device and method for monitoring formation soil deformation during hydrate formation and exploitation, and belongs to the field of new energy development experiments. Background technique [0002] Natural Gas Hydrate, also known as "combustible ice", is an ice, crystalline, supramolecular, and clathrate compound formed by water and natural gas in a specific high-pressure and low-temperature environment. It is mainly distributed in oceans and Terrestrial permafrost, where marine gas hydrate resources are global. The salient features of natural gas hydrate are wide distribution, large reserves, high density and high calorific value. Under standard conditions, 1m 3 The natural gas hydrate can release 164m 3 methane gas and 0.8m 3 water. It is estimated that the total amount of natural gas hydrate resources in the world is converted into methane gas, and its organic carbon reserves are equivalent to twice that of the world's ...

AI Technical Summary

Problems solved by technology

However, compared with conventional oil and gas fields, the distribution of hydrate is shallower, and the overburden and hydrate formation layers are both permeable layers and unconsolidated diagenetic. The process of hydrate decomposition to form gas phase and liquid phase makes each phase in the reservoir The saturation, effective porosity, and permeability of hydrates will change dynamically with the decomposition of hydrates, which will affect the stability of the formation and may cause geological disasters such as reservoir collapse and even submarine landslides.

[0004] As an emerging energy source, natural gas hydrate has a relatively weak research foundation. In order to fully study its physical and chemical properties and possible formation stability issues, there are currently many indoor test devices. However, limited by experimental conditions and the special properties of hydrate, The research on the stability of hydrate formations is mostly explored through numerical simulation, combined with laboratory test observations, etc., it is difficult to directly obtain formation deformation data, and there is a lack of objective understanding of reservoir soil deformation during hydrate mining, and it is impossible to analyze the hydrate formation conditions under mining conditions. Observation of Soil Deformation Effect in Reservoir

In addition, at present, point or linear monitoring methods are usually used for soil deformation monitoring under experimental conditions. The continuity of monitoring data is poor, which cannot effectively reflect the spatial characteristics of soil deformation in key planes, and the transmission frequency is low, which often cannot realize real-time monitoring.

Images